I am swapping out the factory rims for custom rims. Nothing fancy like 20's. I am old school. Currently my 69 Cutlass S has 14s on the front and 15s on the rear. Over the years I have redone the springs on the car so that it has the heavy springs on it to make it look like a gasser. The question is or what would be the benefit of changing the front to 15s. What could I run into for issues, besides tire rub if I get to large of rubber?

 

Don't confuse rim diameter with tire diameter. The only things that matter as far as tire rubbing are:

1) Tire (not wheel) outside diameter
2) Tire (not wheel) width
3) Wheel offset

You can easily find a lower profile 15" tire that's no larger in diameter than your current 14" tires.

 

Are you wanting to change the gasser look or keep it?

 

Keep the gasser look. I think it is a mean look and something different. I have found the rims 5 slot in both sizes used. I know that if I did a disk conversion that it would come into play but at this time I am getting by on drums. I put stationwagon springs all the way around. Had to put the heavy springs in the front due to a 350 to 455 swap. At this time I have 14 with 215 on the front and 15 with 255 big meats on the rear. If I go with 15's on the front will I run into anything funky or just keep my space involved.

 

This car is a little older but you could use it as a guidline for appearances. I think a 15 inch wheel would be ok but you should concentrate on a taller tire size instead of a wider tire size. If you were using bias ply tires I would recommend a J78x15. Notice that for a true gasser look you should have a straight front axle.

edit: The style of wheels that car used is pretty typical of those used on gassers in the sixties, as you said, a five spoke pattern. The term "Radir" comes to mind, I think they were a wheel manufacturer back then.

second edit: I just found this link, I think it may help.